1. Field of the Invention
The present invention relates to an instrument for coronary artery bypass graft surgery.
2. Description of the Related Art
In recent years, catheter intervention for a patient suffering from an ischemic heart disease such as myocardial infarction has rapidly come to be popularly performed. Typical methods of the catheter intervention include coronary artery angiodilatation and intravascular stenting, both of which have the advantage of being minimally invasive to a patient, and of requiring only a short stay in a hospital.
On the other hand, for a patient to whom the catheter treatment is not applicable, coronary artery bypass graft (hereinafter simply referred to as CABG) is well known as an effective method. The CABG is an operation of anastomosing an end of a graft vessel detached from for example an internal thoracic artery or gastroepiploic artery, to a peripheral side of the coronary artery suffering stenosis, which is the cause of ischemia, to thereby resolve the ischemia.
Many of the patients who need to undergo the CABG have obstruction or stenosis in a plurality of coronary arteries, calcification in ascending aorta, or a chronic disease in the brain, kidney or a respiratory organ, and are senior aged. Accordingly, a risk originating from the CABG on the part of such patients is far from low. Especially, a riskiest procedure to the patient is extracorporeal circulation, to be performed with a heart lung machine while the patient's heartbeat is stopped. Applying a heart lung machine to a patient suffering from progressed arteriosclerosis is exactly like supplying high-pressure water through a rusted pipe. In other words, substances deposited inside the blood vessel may be swept away and thus obstruct another blood vessel, thereby inducing a complication such as cerebral infarction or the like.
For this type of patients, a procedure of anostomosing a bypass graft while the heart is beating without using a heart lung machine has lately been attempted, and has been achieving excellent results. Such procedure is called “off-pump coronary artery bypass” (hereinafter referred to as OPCAB).
A drawback of the OPCAB is that a lot of skill is required for performing an anastomosis to perfection in a short time, since the patient's heart keeps beating during the operation. In the event that an anastomosis has been imperfectly performed, a blood clot may be formed in an area including the anastomosed point, the coronary artery and the graft vessel, to thereby cause obstruction. This problem, however, has been solved by utilizing a stabilizer, which restrains a motion of the part to be anastomosed, thereby facilitating an anastomosis of the graft vessel under a stabilized state. As a result, because of improvement in precision of anastomosis, outcome of the OPCAB procedure has shown a dramatic improvement (U.S. Pat. No. 5,836,311 Specifications).
Further, the international patent application whose publication number is WO02/054937 discloses a device for holding the heart by a suction pressure to adjust a position of thereof, to improve precision of anastomosis of an affected part that cannot be brought into view under a normal heart orientation and is hence difficult to perform an anastomosis. The device disclosed in the international patent application is provided with a suction pad capable of adsorbing to a heart wall surface, an arm for adjusting a position of the suction pad, and a vacuum tube communicated with the suction pad and connectable to a vacuum source. However, this device utilizes a force in only one direction to adjust a position of the heart. Accordingly, the heart may shift from an appropriate position or even fall off from the device, during an anastomosis procedure with the heart held in a certain position.